Establishing effective interpretation criteria in hair analysis to distinguish between passive and active cocaine exposure: Insights from authentic hair samples collected from professional individuals exposed to cocaine.

Interpretation results of hair analysis, particularly for cocaine, can be challenging due to the need to differentiate between active use or passive contamination. Our study aimed to assess the impact of varying degrees of passive cocaine exposure hair analysis results and their interpretation. Hair samples (n = 25) were categorized based on the declared cocaine exposure of volunteers: (a) high, involving handling up to several kilograms of cocaine powder from dismantling illegal distribution sites; (b) medium, where staff dealt with cocaine blocks (up to kilograms); and (c) low, with staff in contact with up to grams of cocaine for laboratory analysis. Hair samples were decontaminated using dichloromethane, water, and methanol. The samples and final wash were analyzed for cocaine, benzoylecgonine, norcocaine, cocaethylene, m-OH-benzoylecgonine, and ecgonine methyl ester using a validated UPLC-MS/MS method. Cocaine hair concentrations ranges were as follows (pg/mg): high (n = 53 segments) < LLOQ(32)-7046; medium (n = 91) < LLOQ-939; and low (n = 54) < LLOQ-292. All hair samples had concentrations below the LLOQ for cocaethylene, ecgonine methyl ester, and m-OH-benzoylecgonine. Applying the SoHT cocaine cut-off in combination with a hair/wash ratio criterion identified 97% of the samples as contaminated. This study advocates for a comprehensive approach in evaluating cocaine hair concentrations. This involves integrating the 500 pg/mg decision limit for cocaine with a criterion comparing wash and hair concentration. Additionally, confirming the presence of specific metabolites is crucial. This multifaceted method effectively distinguishes between environmental contamination and active cocaine usage. The research contributes significantly to refining cocaine exposure assessment in professional contexts.

Cannabis profiling of seized samples: An intra-location variability study using gas chromatography-mass spectrometry profiles and multivariate data analysis.

Yearly, cannabis belongs to the most seized drugs worldwide. During judicial investigations, illicit cannabis profiling can be performed to compare seized herbal material. However, comparison is challenging because of the natural heterogeneity of the psychoactive crop. Gas chromatography-mass spectrometry (GC-MS) profiles, consisting of eight cannabinoids, were used to study the intra-location (within) and inter-location (between) variabilities. Decision thresholds were derived from the 95% and 99% confidence limits, applying Pearson correlation coefficients for the intra-location samples. The false negatives and false positives (FPs) determined the discriminative power of different pretreatments applied to obtain the lowest FP error rate possible. Initially, a 97 samples data set was used and with log transformation as pretreatment, a decrease in FPs from 38% and 45% FPs to 17% and 22%, for both confidence limits, respectively, was seen relative to internal standard normalization that was used as reference. An additional intra-plantation variability study with 130 samples verified whether the initial model contained sufficient within-location information, but this was not the case. Hence, a combined data matrix was constructed with all seized samples. Log transformation provided the best FP results for both limits, that is, an improvement from 58% and 64% to 21% and 26%, respectively, was seen. The representativeness of these 'linked' thresholds was demonstrated using both cross-validation and an external set, for which similar FP results as for the calibration set were obtained. By applying data pretreatment, a significant improvement was observed to distinguish seized samples. However, the FP rate is still not at an acceptable level to defend in court.

Incorporation of doxylamine and N-doxylamine-oxide in human hair and the impact of a permanent oxidative hair dye.

Knowledge of the drug incorporation in hair and impact of cosmetic treatments remains essential to correctly interpret forensic cases. The study shows the analysis of doxylamine and doxylamine-N-oxide and the evaluation of the relationship between dose and hair concentration and the impact of hair treatment (oxidative dying). The study included (A) three subjects participated to the study: a regular user (Subject 1) and two single-dose users (Subject 2, 1 single dose; and Subject 3, 2 single doses spaced 5 months apart). Subject 3 applied a permanent oxidative hair dying monthly. (B) A permanent oxidative hair dying was applied twice to the hair collected from Subject 2. (A) The average concentrations in head hair for doxylamine and its N-doxylamine-oxide, respectively, were as follows: Subject 1, 1825 pg/mg and 16 pg/mg; Subject 2, 182 and

Combined Use of Flubromazepam and Stimulants: Blood and Oral Fluid Concentrations and Impact on Driving Ability.

"Designer" benzodiazepines (DBZDs) are becoming increasingly available in Europe, with the European Monitoring Centre of Drugs and Drug Addiction currently monitoring ∼30 new benzodiazepines. The following driving under the influence of drug (DUID) case describes the oral fluid (OF) and blood concentrations, as well as the observed effects after the combined use of stimulants and flubromazepam. Both OF, collected via the Intercept i2 collector (Immunalysis, Pomona, CA, USA), and blood (collected in containers with various stabilizers) were screened using a liquid chromatographic (LC) time-of-flight (TOF) mass spectrometric (MS-MS) method. In addition, various LC-MS-MS methods in multi-reaction monitoring mode were applied for confirmation and quantification. The OF and blood samples were taken 2 h 25 min and 9 h 19 min after the accident, respectively. OF contained 789 ng/mL amphetamine, 5,173 ng/mL MDMA, 168 ng/mL benzoylecgonine, 492 ng/mL cocaine, 134 ng/mL 4-methylmethcathinone (4-MMC) and traces of flubromazepam (less than limit of quantification (LLOQ); 2 ng/mL). The sodium-fluoride blood samples contained 19 ng/mL amphetamine, 284 ng/mL MDMA, 20 ng/mL MDA, 38 ng/mL benzoylecgonine, 4 ng/mL methylecgonine, 161 ng/mL flubromazepam and traces of 4-MMC (

Real-time electrochemical screening of cocaine in lab and field settings with automatic result generation.

This work presents the results of a novel application for the fast on-site screening of cocaine and its main cutting agents in suspicious and confiscated samples. The methodology behind the novel application consists of portable electrochemical detection coupled with a peak recognition algorithm for automated result output generation, validated both in laboratory and field settings. Currently used field tests, predominantly colorimetric tests, are lacking accuracy, often giving false positive or negative results. This presses the need for alternative approaches to field testing. By combining portable electrochemical approaches with peak recognition algorithms, an accuracy of 98.4% concerning the detection of cocaine was achieved on a set of 374 powder samples. In addition, the approach was tested on multiple "smuggled," colored cocaine powders and cocaine mixtures in solid and liquid states, typically in matrices such as charcoal, syrup, and clothing. Despite these attempts to hide cocaine, our approach succeeded in detecting cocaine during on-site screening scenarios. This feature presents an advantage over colorimetric and optical detection techniques, which can fail with colored sample matrices. This enhanced accuracy on smuggled samples will lead to increased efficiency in confiscation procedures in the field, thus significantly reducing societal economic and safety concerns and highlighting the potential for electrochemical approaches in on-the-spot identification of drugs of abuse.

Evaluation of decontamination procedures for drug testing in undamaged versus damaged hair.

Although substances incorporated by ingestion are strongly bound to hair, their loss may occur if aggressive decontamination procedures are applied, especially in highly damaged/porous hair. Evaluation of cleaning procedures using hair samples with different porosity obtained from ethanol or drug users (cocaine, heroin, methamphetamine, methadone, fentanyl, tramadol, diazepam, buprenorphine, dihydrocodeine, citalopram and trazodone). The effect of washing time and multiple wash steps with water and methanol were evaluated. Hair samples (n = 16) were selected and evaluated according to (a) the drug pattern consumption, (b) available amount, and (c) hair porosity (c1 'cosmetic treatment', c2: storage time). Six of them were soaked with an aqueous deuterated analogue solution. The samples were cut in 1-cm segments and homogenized. All hair samples were then decontaminated one or six times with 1.5 ml of water or methanol during 1, 5, 15, 30, 60 and/or 90 min (n = 1 to 3/sample, depending on the available amount of hair). Hair extracts were then cleaned up via a solid-phase extraction (SPE) or liquid-liquid extraction (LLE), while the washes were evaporated to dryness. All were thereafter reconstituted and analysed with routine ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) methods. Although concentrations of parent drugs and/or metabolites presented a negative trend along the washing time with methanol (up to 80%), the compounds were relatively well retained in hair even after a 90 min wash (with methanol or water) in most samples, and their retention would depend mostly on the hair nature rather than their physicochemical properties (whether incorporated by ingestion and/or from external contamination). Moreover, parent drugs and/or metabolites were detected in the washes in most samples, and the ratio between hair and washes decreased along the washing time. More than 50% of the deuterated analogues soaked into hair were still present after the different washing steps. Losses were observed more frequently for long-term stored hair samples, after decontamination with methanol for more than 30 min. Therefore, prolonged or repeated cleaning with methanol should be avoided in general procedures.

Gas Chromatographic Fingerprint Analysis for the Comparison of Seized Cannabis Samples.

Cannabis sativa L. is widely used as recreational illegal drugs. Illicit Cannabis profiling, comparing seized samples, is challenging due to natural Cannabis heterogeneity. The aim of this study was to use GC-FID and GC-MS herbal fingerprints for intra (within)- and inter (between)-location variability evaluation. This study focused on finding an acceptable threshold to link seized samples. Through Pearson correlation-coefficient calculations between intra-location samples, 'linked' thresholds were derived using 95% and 99% confidence limits. False negative (FN) and false positive (FP) error rate calculations, aiming at obtaining the lowest possible FP value, were performed for different data pre-treatments. Fingerprint-alignment parameters were optimized using Automated Correlation-Optimized Warping (ACOW) or Design of Experiments (DoE), which presented similar results. Hence, ACOW data, as reference, showed 54% and 65% FP values (95 and 99% confidence, respectively). An additional fourth root normalization pre-treatment provided the best results for both the GC-FID and GC-MS datasets. For GC-FID, which showed the best improved FP error rate, 54 and 65% FP for the reference data decreased to 24 and 32%, respectively, after fourth root transformation. Cross-validation showed FP values similar as the entire calibration set, indicating the representativeness of the thresholds. A noteworthy improvement in discrimination between seized Cannabis samples could be concluded.

The Interest of a Systematic Toxicological Analysis Combined with Forensic Advice to Improve the Judicial Investigation and Final Judgment in Drug Facilitated Sexual Assault Cases.

The conviction rate in drug facilitated sexual assault (DFSA) cases is known to be very low. In addition, the potential impact of toxicological results on the case is often not well understood by the judicial authorities. The aims of this study were (1) to obtain more knowledge concerning the prevalence of incapacitating substances in DFSA cases, (2) to create a more efficient DFSA analysis strategy taking background information into account, and (3) to evaluate the potential impact of systematic toxicological analysis (STA) on the final judicial outcome. This small-scale epidemiological study (n = 79) demonstrates that 'commonly-used' illicit drugs, psychoactive medicines and ethanol are more prevalent in DFSA cases in contrast to the highly mediatized date rape drugs. Additionally, via case examples, the interest of performing STA-to prove incapacitation of the victim-in judicial procedures with mutual-consent discussions has been demonstrated as it led to increased convictions. However, more attention has to be paid to ensure a short sampling delay and to get more accurate information from the medical treatment of the alleged victim. This will improve the interpretation of the toxicological analysis and thus its applicability in a DFSA case. The future is multi-disciplinary and will certainly lead to an efficient and more cost-effective DFSA approach in which STA can impact the final judgment.

Comparison of Spectroscopic Techniques Combined with Chemometrics for Cocaine Powder Analysis.

Spectroscopic techniques combined with chemometrics are a promising tool for analysis of seized drug powders. In this study, the performance of three spectroscopic techniques [Mid-InfraRed (MIR), Raman and Near-InfraRed (NIR)] was compared. In total, 364 seized powders were analyzed and consisted of 276 cocaine powders (with concentrations ranging from 4 to 99 w%) and 88 powders without cocaine. A classification model (using Support Vector Machines [SVM] discriminant analysis) and a quantification model (using SVM regression) were constructed with each spectral dataset in order to discriminate cocaine powders from other powders and quantify cocaine in powders classified as cocaine positive. The performances of the models were compared with gas chromatography coupled with mass spectrometry (GC-MS) and gas chromatography with flame-ionization detection (GC-FID). Different evaluation criteria were used: number of false negatives (FNs), number of false positives (FPs), accuracy, root mean square error of cross-validation (RMSECV) and determination coefficients (R2). Ten colored powders were excluded from the classification data set due to fluorescence background observed in Raman spectra. For the classification, the best accuracy (99.7%) was obtained with MIR spectra. With Raman and NIR spectra, the accuracy was 99.5% and 98.9%, respectively. For the quantification, the best results were obtained with NIR spectra. The cocaine content was determined with a RMSECV of 3.79% and a R2 of 0.97. The performance of MIR and Raman to predict cocaine concentrations was lower than NIR, with RMSECV of 6.76% and 6.79%, respectively and both with a R2 of 0.90. The three spectroscopic techniques can be applied for both classification and quantification of cocaine, but some differences in performance were detected. The best classification was obtained with MIR spectra. For quantification, however, the RMSECV of MIR and Raman was twice as high in comparison with NIR. Spectroscopic techniques combined with chemometrics can reduce the workload for confirmation analysis (e.g., chromatography based) and therefore save time and resources.

Electrochemical analysis of speedball-like polydrug samples.

Increasing global production, trafficking and consumption of drugs of abuse is an emerging threat to people's health and safety. Electrochemical approaches have been proved to be useful for on-site analysis of drugs of abuse. However, less attention has been focused on the analysis of polydrug samples, even though these samples pose severe health concerns, especially when stimulants and depressants are combined, as is the case of speedball, a mixture of cocaine and heroin. In this work, we provide solutions for the selective detection of cocaine (stimulant) in polydrug samples adulterated with heroin and codeine (depressants). The presence of either one of these compounds in cocaine street samples leads to an overlap with the cocaine signal in square-wave voltammetry measurements at unmodified carbon screen-printed electrodes, leading to inconclusive screening results in the field. The provided solutions to this problem consist of two parallel approaches: (i) cathodic pretreatment of the carbon screen-printed electrode surface prior to measurement under both alkaline and neutral conditions and (ii) electropolymerization of orthophenylenediamine on graphene modified carbon screen-printed electrodes prior to measurement under neutral conditions. Both strategies allow simultaneous detection of cocaine and heroin in speedball samples as well as simultaneous detection of cocaine and codeine. Implementing these strategies in portable devices holds great potential for significantly improved accuracy of on-site cocaine screening in polydrug samples.

Identifying Electrochemical Fingerprints of Ketamine with Voltammetry and Liquid Chromatography-Mass Spectrometry for Its Detection in Seized Samples.

Herein, a straightforward electrochemical approach for the determination of ketamine in street samples and seizures is presented by employing screen-printed electrodes (SPE). Square wave voltammetry (SWV) is used to study the electrochemical behavior of the illicit drug, thus profiling the different oxidation states of the substance at different pHs. Besides, the oxidation pathway of ketamine on SPE is investigated for the first time with liquid chromatography-high-resolution mass spectrometry. Under the optimized conditions, the calibration curve of ketamine at buffer solution (pH 12) exhibits a sensitivity of 8.2 µA µM-1, a linear relationship between 50 and 2500 µM with excellent reproducibility (RSD = 2.2%, at 500 µM, n = 7), and a limit of detection (LOD) of 11.7 µM. Subsequently, binary mixtures of ketamine with adulterants and illicit drugs are analyzed with SWV to investigate the electrochemical fingerprint. Moreover, the profile overlapping between different substances is addressed by the introduction of an electrode pretreatment and the integration of a tailor-made script for data treatment. Finally, the approach is tested on street samples from forensic seizures. Overall, this system allows for the on-site identification of ketamine by law enforcement agents in an easy-to-use and rapid manner on cargos and seizures, thereby disrupting the distribution channel and avoiding the illicit drug reaching the end-user.

A different insight in hair analysis: Simultaneous measurement of antipsychotic drugs and metabolites in the protein and melanin fraction of hair from criminal justice patients.

BACKGROUND: Previous studies have postulated that four structural compartments may be differentiated in hair: surface protein domain, water-accessible protein domain, water-inaccessible protein domain, and melanin. Drugs contained in blood, sweat, sebum, and environment would be deposited in the first two domains, with primarily drugs in blood being incorporated in the latter two domains during hair synthesis. Drugs in the first two domains would be removed by washing procedures. Use of enzymatic extraction procedures and evaluation of hair for damage from harsh cosmetic treatments might help to separately identify and quantify the drugs incorporated in the second two domains. AIMS: a) Development of an UPLC-MS/MS method for the simultaneous quantification of the following 19 antipsychotic drugs and metabolites in hair: amisulpride, aripiprazole, chlorpromazine, clotiapine, clozapine, desmethylclozapine, desmethylolanzapine, haloperidol, norchlorpromazine, 7-OH-quetiapine, 9-OH-risperidone, olanzapine, pimozine, pimpamperone, quetiapine, risperidone, sertindole, sulpride, and tiapride; b) evaluation of measurement of patient adherence to prescribed medication use, c) determination of the influence of biochemical individuality effects on hair drug content, d) evaluation of relative binding of antipsychotic drugs to protein and to melanin hair structures. METHOD: Approximately 10 mg of intact hair were decontaminated with isopropanol and phosphate buffer, and then enzymatically digested overnight with dithiothreitol. After centrifugation, the supernatant digest (protein fraction) was separated from the remaining melanin hair pellet (melanin fraction). Melanin fraction was washed with water, and the drugs were extracted with dimethyl sulfoxide with ball-mill pulverization. Both fractions were purified with solid-phase cation exchange cartridges and injected in the UHPLC-MS/MS system. RESULTS AND DISCUSSION: Validation of the method was carried out on the protein fraction following international guidelines. The limits of quantification ranged from 1.6-40 pg/mg. The method was applied to 59 head hair samples from prisoners from an antipsychotic compliance study in the criminal justice system in US. The patients were under chlorpromazine, haloperidol, risperidone, olanzapine, or quetiapine multiple antipsychotic treatment, during incarceration. The first head hair centimeter, closest to the scalp, was analyzed. The results were evaluated in relation to the type of hair, colour, hair damage, drug melanin affinity, and prescribed dose. In general, no good correlation between the prescribed dose/concentration in hair was obtained. A wide range of antipsychotic concentrations were observed 'dose mg/day (d); pg/mg protein fraction (A)': chlorpromazine (d:50-400;A:1600) and its metabolite norchlorpromazine (A: 1600), haloperidol (d:4-20;A: 1600) and its metabolite 9-OH-quetiapine (A:

Development of an UPLC-MS/MS method for the analysis of 16 synthetic opioids in segmented hair, and evaluation of the polydrug history in fentanyl analogue users.

Seizures of synthetic opioids have increased since 2012, with a 45 % increase in synthetic opioid related deaths between 2016 and 2017 in US. Recently, concerns have arisen around these substances and their illicit use also in several European countries. Our aim was to develop and validate an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the analysis of 16 synthetic opioids in segmented hair, including fentanyl, norfentanyl, acetylfentanyl, U-47700, AH-7921, acrylfentanyl, crotonylfentanyl, butyrylfentanyl, methoxacetylfentanyl, U-49900, valeryfentanyl, 4-fluoro-iso-butyrylfentanyl, ocfentanyl, furanylfentanyl, tetrahydrofuranylfentanyl, and alfetanyl. Sample preparation involved washing the hair in dichloromethane, water and methanol, and extraction in methanol, followed by solid phase extraction clean-up. This method was validated for linearity, limit of quantification (LLOQ), precision and bias, selectivity, stability, matrix effects, extraction efficiency of the clean up procedure, and carryover. LLOQs ranged from 0.15-1pg/mg, and the calibration ranged from the LLOQ up to 500pg/mg. Intra and inter-day precision were evaluated at low and high concentrations, with spiked QCs, during 8 days and the results were satisfactory with RSD<15 % for all the compounds except for norfentanyl (22 %) and alfentanyl (19 %). Two external certified QCs containing fentanyl at 11 and 105pg/mg were also analysed within each batch and the RSD and bias were lower than 16 % and 10 %, respectively. Matrix effects compensated by internal standard fentanyl-d5 (MEIS), were between 77-115 % (RSD<10 %) and extraction efficiency of the clean-up procedure was between 66-93 % (RSD<21 %). Processed sample stability and carryover were acceptable for all of the compounds. The method was applied to 17 authentic hair samples (body or head hair) from US fentanyl analogue users. When head hair was available, the hair strands were analysed in 1cm/segment. Concentrations ranges were as follows: fentanyl (n=16) 2->ULOQ (500) pg/mg, norfentanyl (n=14) 1-38pg/mg, acetylfentanyl (n=7) 0.6->ULOQ (250) pg/mg, furanylfentanyl (n=5) 2-123pg/mg, tetrahydrofuranylfentanyl (n=1) 0.5-63pg/mg and valerylfentanyl (n=1) 2.1->ULOQ (50) pg/mg, along the hair strands. To our knowledge, this is the first time where concentrations of tetrahydrofuranylfentanyl, and valerylfentanyl in hair are reported. The same samples were also analysed for the determination of other drugs of abuse using our routine method (also in 1cm/segment for head hair when available). The results demonstrated poly-drug use in these fentanyl-analogue users population (mean drugs: n=5): amphetamine and/or methamphetamine (n=10), buprenorphine (n=5), cocaine (n=8), methadone (n=8), 6-MAM (n=17), meperidine (n=1), oxycodone (n=11), tramadol (n=3). Evaluation of the concentrations of these drugs, together with the fentanyl analogues is discussed in the present paper. Two authentic samples from two Belgian post-mortem cases, were also analysed showing fentanyl use and in one case polydrug use. The results demonstrated multi-analyte quantitative methods, including fentanyl analogues, are becoming useful in forensic laboratories involved in hair analysis, and in particular when polydrug use is suspected.

Unraveling the Mechanisms Behind the Complete Suppression of Cocaine Electrochemical Signals by Chlorpromazine, Promethazine, Procaine, and Dextromethorphan.

The present work investigates the challenges accompanied by the electrochemical cocaine detection in physiological conditions (pH 7) in the presence of chlorpromazine, promethazine, procaine, and dextromethorphan, frequently used cutting agents in cocaine street samples. The problem translates into the absence of the cocaine oxidation signal (signal suppression) when in a mixture with one of these compounds, leading to false negative results. Although a solution to this problem was provided through earlier experiments of our group, the mechanisms behind the suppression are now fundamentally investigated via electrochemical and liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) strategies. The latter was used to confirm the passivation of the electrodes due to their interaction with promethazine and chlorpromazine. Electron transfer mechanisms were further identified via linear sweep voltammetry. Next, adsorption experiments were performed on the graphite screen printed electrodes both with and without potential assistance in order to confirm if the suppression of the cocaine signals is due to passivation induced by the cutting agents or their oxidized products. The proposed strategies allowed us to identify the mechanisms of cocaine suppression for each cutting agent mentioned. Suppression due to procaine and dextromethorphan is caused by fouling of the electrode surface by their oxidized forms, while for chlorpromazine and promethazine the suppression of the cocaine signal is related to the strong adsorption of these (nonoxidized) cutting agents onto the graphite electrode surface. These findings provide fundamental insights in possible suppression and other interfering mechanisms using electrochemistry in general not only in the drug detection sector.

Time course detection of dihydrocodeine in body hair after a single dose.

BACKGROUND: When head hair is not suitable or not available, body hair, such as leg or beard hair might be the most suitable sample for drug hair analysis. Information about the time course of drugs in hair, from the different anatomical body sites, should still be well documented. AIM: The aim of this study was to determine and compare (a) the detection window of dihydrocodeine in frequently shaved legs and beard, (b) in unshaved hair from head hair, chest hair, leg hair, and/or arm hair, and (c) the distribution concentrations over the scalp, after a single dihydrocodeine intake. METHOD: Before a single intake of 12 mg dihydrocodeine by subject 1 (woman), both legs hair were shaved in the morning. The subject 2 (man) shaved his beard in the morning and 30 min later he had a dose of 10 mg of dihydrocodeine. The samples were washed with water and shampoo, dried and collected as follows: Subject 1: every 3-days shaved leg hair (n = 9) and 1-month-later head hair (n = 1). Subject 2: daily shaved beard hair (n = 15), 2 months later head hair (n = 145), and every 20 days unshaved arm, leg and chest hair (from different areas) (n = 4/area). The samples were analysed for dihydrocodeine using a validated liquid chromatography-tandem mass spectrometry method with a limit of quantification (LOQ) of 15.6 pg/mg for dihydrocodeine. About 20 mg of hair samples were weighted, washed with dichloromethane, centrifuged, dried, and pulverized in the same disposable tubes. Then the samples were incubated with methanol (under sonication at 45 °C) during 4 h. After centrifugation, the supernatant was evaporated and a cation exchange solid phase extraction followed by separation and quantification using ultra performance liquid chromatography-tandem mass spectrometry (ULC-MS/MS) was carried out. Chromatographic separation was achieved using a BEH phenyl column eluted with 0.1% formic acid: methanol (0.1% formic acid). The UPLC-MS/MS method was validated and used in routine for drug hair analysis for already several years. RESULTS AND DISCUSSION: In the present study leg hair was collected every 3 days, as an average of frequent shaved hair in western woman population. Shaved leg hair was very limited and only one hair sample was available per analysis. Beard was collected daily and in a higher amount. Dihydrocodeine was detected in leg hair from the first sample (3 days after the intake). Maximum concentration at 68 pg/mg for the single intake was obtained after 15 days (±2 days), decreasing later to the LOQ from the 21th day. Beard hair was positive from the first day sample, and the maximum concentration was observed at 66 pg/mg, 6 days after the intake, decreasing later to the LOQ from day 13. This may be explained by growth rate and the amount of growing hairs, in anagen phase. In other body hair samples, dihydrocodeine was negative or detected from 1 month after the intake. No significant differences in dihydrocodeine concentrations over the scalp in the different regions were observed (p > 0.05). CONCLUSION: Body hair presents different time course window detection due to the different growth rates. Frequently shaved leg and beard hair may be suitable samples for recent single dihydrocodeine dose detection from the first days up to 2-3 weeks after the intake, respectively, when a LOQ of 15.6 pg/mg is applied.

Electrochemical Strategies for Adulterated Heroin Samples.

Electrochemical strategies to selectively detect heroin in street samples without the use of complicated electrode modifications were developed for the first time. For this purpose, heroin, mixing agents (adulterants, cutting agent, and impurities), and their binary mixtures were subjected to square wave voltammetry measurements at bare graphite electrodes at pH 7.0 and pH 12.0, in order to elucidate the unique electrochemical fingerprint of heroin and mixing agents as well as possible interferences or reciprocal influences. Adjusting the pH from pH 7.0 to pH 12.0 allowed a more accurate detection of heroin in the presence of most common mixing agents. Furthermore, the benefit of introducing a preconditioning step prior to running square wave voltammetry on the electrochemical fingerprint enrichment was explored. Mixtures of heroin with other drugs (cocaine, 3,4-methylenedioxymethamphetamine, and morphine) were also tested to explore the possibility of their discrimination and simultaneous detection. The feasibility of the proposed electrochemical strategies was tested on realistic heroin street samples from forensic cases, showing promising results for fast, on-site detection tools of drugs of abuse.

Influence of bleaching and thermal straightening on endogenous GHB concentrations in hair: An in vitro experiment.

Since gamma-hydroxybutyric acid (GHB) is present in hair of the general population under physiological concentrations, special attention has to be given to the hair analysis of GHB and its interpretation. Normal levels of endogenous GHB can vary in each individual. As a result, strands of hair from a subject have to be cut in small segments (0.3-0.5 cm long) with analysis of each segment. As such, each subject can be used as its own control with a continuous endogenous signal. If one segment has a GHB concentration 10 times higher than the others, this suggests possible administration of exogenous GHB according to the UNODC guideline for Drug Facilitated Assault Cases. AIM: As cosmetic treatments were found to decrease drug concentrations in hair, the aim of the study was to develop an UPLC®-MS/MS method for the analysis of GHB in hair. An in vitro study was then carried out in order to evaluate the impact of a hair straightener or a bleaching treatment on endogenous GHB concentrations. METHOD: Hair samples (10 mg) were washed with dichloromethane and water. After drying overnight in an oven at 35 °C the samples were pulverized in disposable plastic tubes. Methanol/acetonitrile/ammonium formate buffer 1 mM (25:25:50, v/v/v) was used to extract the drug from the hair matrix in a water bath for 1.5 h at 37 °C. Thereafter, the samples were filtered and evaporated to dryness. The dried extracts were then reconstituted in mobile phase and injected in a UPLC®-MS/MS (Waters, Winslow, UK) with a BEH C18 column. RESULTS: The method was validated using untreated hair samples from three healthy volunteers. The calibration curve ranged from 0.06 to 25 ng/mg and the repeatability and intra-batch precision was lower than 20% evaluated in 8 different batches. Processed samples were stable for 3 days in the auto-sampler. To demonstrate the method applicability, 54 hair samples from healthy volunteers were analysed for endogenous GHB resulting in a concentration range from 0.2 to 6 ng/mg. Three different hair treatments experiments were carried out, in which a hair straightener and/or a bleaching treatment were applied. These experiments demonstrated that hair treatments decreased up to 80% of the GHB endogenous concentrations. CONCLUSION: This in vitro study showed that hair bleaching or a heat source treatment influences GHB concentrations in hair. For a correct interpretation of GHB results in hair, cosmetic treatments should be considered, certainly in cases where only a part of the hair is treated.

Tackling Poor Specificity of Cocaine Color Tests by Electrochemical Strategies.

This paper presents electrochemical strategies for the fast screening of cocaine and most common cutting agents found in seized drug samples. First, a study on the performance of Scott color tests on cocaine and a wide range of cutting agents is described. The cutting agents causing false positive or false negative results when in mixture with cocaine are identified. To overcome the lack of specificity of color tests, we further propose a fast screening strategy by means of square wave voltammetry on disposable graphite screen printed electrodes, which reveals the unique fingerprint of cocaine and cutting agents. By employing a forward and backward scan and by a dual pH strategy, we enrich the electrochemical fingerprint and enable the simultaneous detection of cocaine and cutting agents. The effectiveness of the developed strategies was tested for the detection of cocaine in seized cocaine samples and compared with the color tests. Moreover, we prove the usefulness of square wave voltammetry for predicting possible interfering agents in color tests, based on the reduction peak of cobalt thiocyanate. The developed electrochemical strategies allow for a quick screening of seized cocaine samples resulting in a selective identification of drugs and cutting agents.

New psychoactive substances in oral fluid of French and Belgian drivers in 2016.

BACKGROUND: Driving under the influence of drugs (DUID) is a worldwide problem with potentially major judiciary and life-threatening consequences. Up to now, only classical drugs of abuse (DOA) are tested for DUID detection. A challenging issue for drafting up-dated international drug policies is to take into account the recent and expanding new psychoactive substances (NPS) market. NPS consist in various narcotic or psychotropic drugs, most of them having a "legal" status, that replicate chemical structures and/or pharmacological effects of classical DOA. Although it is obvious that NPS can lead to impaired driving, the prevalence of NPS use in a DUID context is unknown since the applied roadside screening tests are not yet adapted for these compounds. METHODS: Between January and December 2016, a total of 391 oral fluid specimens were obtained from used roadside immunochemical test devices for DOA (Drugwipe-5S® device). These specimens were analyzed using liquid chromatography coupled with tandem mass spectrometry and high resolution mass spectrometry. RESULTS: NPS (mainly cathinone derivatives) were detected in 33 out of the 391 oral fluid samples. This NPS positivity rate of 8.4% in oral fluid of drivers who were submitted to a roadside drug testing in 2016 in France and in Belgium is comparable to the available blood data (NPS positivity rate of 7%) observed in 2015 in similar populations. CONCLUSION: Our results demonstrate the reality of driving after NPS use in French and Belgian drivers who were submitted to a roadside DOA test. As there is a lack of on-site detection methods to screen for NPS, the detection of NPS in a rapid and cost-effective DUID detection strategy is currently impossible. The expanding use of NPS, notably by drivers as reported here, and the inability of currently used drug detection tests, should be urgently addressed by road safety and law enforcement authorities.